Fluorouracil is a commonly prescribed topical medication for resolving actinic keratoses (precancerous lesions that may lead to squamous cell skin cancer). This chemotherapy agent has a good reputation for clearing AKs. However, it has a very poor track record for patient compliance. The side effects can be quite unpleasant. Since the cream must be used over a time period of many weeks to be effective, it’s not uncommon for patients to simply quit the course of treatment when the discomfort becomes too severe. This medication is applied at home making it easy for patients to skip doses or taper off without even notifying their dermatologist. This means non-compliance rates may be even higher than suspected.
Traditional Dosing Leads to Excessive Adverse Effects
The medicine causes inflammation including swelling, redness, and burning. The treated skin may also crust over. Other potential side effects include dryness, scaling, itching, tenderness, skin erosion, and hyperpigmentation. Patients with sensitive skin are particularly likely to discontinue therapy because of these problems. Now, evidence suggests that the 5% fluorouracil formulation often prescribed is probably overkill. Patients who receive a 0.5% strength cream actually see about the same amount of resolution for their actinic keratoses as those receiving the much higher concentration of active ingredient.
Patients Stay on Course with Lower Dose
In one small study using the lower strength fluorouracil, more than 8 out of 10 patients stuck with their prescribed regimen for the entire course of treatment – a surprisingly high percentage considering that most did experience some adverse effects. This is likely due to the fact that most reported side effects were mild to moderate rather than moderate to severe. Dermatologists who have experienced difficulty getting patients to follow treatment instructions may begin prescribing this lower dosage to increase both patient compliance and patient satisfaction. Being able to offer a similar success rate (around 62% clearance of AKs) with one tenth the amount of fluorouracil also makes this therapy less expensive.
Combo Therapy May Prove Even Better
Some practitioners are finding that they can boost effectiveness even more by combining cryotherapy with 0.5% fluorouracil. Starting out by freezing off the top layer of affected skin may allow better penetration of the topical chemotherapy agent.